The present invention is directed, in general, to fertilizers and, more specifically, to systems and methods for producing organic fertilizer from raw manure, and organic fertilizer manufactured using said systems or methods, wherein said organic fertilizer has a moisture content substantially less than an initial moisture content and a live bacteria content substantially equal to an initial live bacteria content of the raw manure.
Confined animal feeding operations, where raw manure is collected and stockpiled, are increasingly becoming an environmental concern throughout the world. It is estimated that such feeding operations produce up to 1.4 billion tons of manure per year, and stockpiles of manure and other waste products are becoming a major focus of various state regulatory agencies and the U.S. Environmental Protection Agency. Consequently, a problem that must be addressed is how to adequately dispose of or recycle raw manure.
Raw manure, when properly processed, can be used to satisfy the ever increasing demand for natural, organic fertilizers. Processed manure can also be used as a soil amendment for such areas as parks, golf courses and lawns. In various known systems, raw manure is mechanically milled or ground with hammermills or grinders prior to a process in which the manure is dried in a rotary drum dryer at between about 350 and 500 degrees Fahrenheit. A roll compactor is used to form briquets from the pulverized and dried raw manure, which are then reground to a desired granule size. Although there is a demand for recycled raw manure, such prior art systems and methods have not proved satisfactory for both environmental and economic reasons.
First, conventional systems used to recycle raw manure into organic fertilizer have involved complex methods of pulverizing, drying, and compacting. Second, the expense associated with such complex methods has made the successful commercialization of organic fertilizers virtually cost prohibitive. Also, the heat generally required for drying the raw manure is not only very expensive, but it also destroys bacteria in the raw manure, which can result in an organic fertilizer product having a live bacteria content less than a desired level. The process of forming pellets from the pulverized and dried raw manure also produces a great amount of airborne particulates that present a potential health and safety hazard, thereby necessitating the use of particulate containment or purifying systems.
Accordingly, there is need in the art for improved systems and methods to produce organic fertilizer from raw manure; such improved systems and methods are preferably more efficient, more cost-effective, and more environmentally-friendly than prior art systems and methods, and should not substantially destroy the desired live bacteria content of the raw manure during the conversion process to organic fertilizer.
To address the above-discussed deficiencies of the prior art, the present invention relates to organic fertilizer produced from raw manure, and systems and methods for the production thereof. Unlike conventional systems and methods used in the manufacture of organic fertilizers, systems and methods employing the principles of the present invention do not necessarily rely on a heating process to deplete the moisture content of raw manure. The elimination of a heating process results in an organic fertilizer product characterized by a live bacteria content substantially equal to the initial live bacteria content of the raw manure. Moreover, the systems and methods disclosed herein are more efficient and ecologically-friendly than conventional systems and methods.
In general embodiments, a high-velocity air stream is injected into at least one substantially-closed chamber, where it interacts with a supply of raw manure; the raw manure can be bovine or other animal waste products. The high-velocity air stream pulverizes and dries the raw manure, whereby an end product having a moisture content substantially less than the initial moisture content and a live bacteria content substantially equal to the initial live bacteria content of the raw manure is produced.
In a specific embodiment described in detail hereinafter, a cyclonic comminution apparatus is used to pulverize and dry the raw manure; alternatively, a first cyclonic comminution apparatus can be used to substantially pulverize the raw manure and a second cyclonic comminution apparatus can be used to substantially dehydrate the raw manure. Preferably, a heat source is not used to facilitate the drying of the raw manure.
A cyclonic comminution apparatus can include an inverted frustoconical chamber, operative to controllably harness the relationships between air-flow velocity and pressure-gradient forces which are naturally present in the cyclonic environment of a tornado or cyclone. An air stream can be accelerated through a venturi to produce an air stream having a desired high-velocity.
A system for producing organic fertilizer according to the principles disclosed herein can further include a roll compactor to form briquets from the pulverized and dehydrated raw manure. The briquets can then be passed through a grinder to reduce the briquets to organic fertilizer pellets of a desired size, and a screening apparatus can be provided to separate ones of the organic fertilizer pellets having a size less than such desired size. Finally, a bagging apparatus can be provided to package the organic fertilizer pellets into convenient sizes for transportation and sale; alternatively, the organic fertilizer pellets can be sold in bulk and loaded directly into a transport vehicle, such as a truck or train.
The foregoing has outlined, rather broadly, the principles of the present invention so that those skilled in the art may better understand the detailed description of the exemplary embodiments that follow. Those skilled in the art should appreciate that the disclosed conception and exemplary embodiments can be used as a basis for designing or modifying other structures and methods for carrying out the same purposes of the present invention, and that such equivalent constructions do not depart from the spirit and scope of the invention in its broadest form, except as specifically limited by the claims recited hereinafter.